The present disclosure relates to a method of applying a conductive material through the use of a printer with a generally continuous fluid stream.
Screen-printing is a commonly used technique for the front side metallization of crystalline silicon solar cells. However, screen printing is reaching technical limitations as manufacturers seek to produce higher efficiency cells and reduce production costs. For example, contact printing methods do not allow photovoltaic suppliers to minimize the silicon used to fabricate cells due to the propensity for increased wafer breakage and scrap. Optional non-contact printing methods for applying contacts to solar cells typically use droplets of fluids containing a conductive material. Inkjet printing is a common method of forming drops; however, inkjet printing can not reliably apply enough conductive material per unit time to sustain state-of-the-art production rates. Also, conductive contacts formed from discrete droplets can result in relatively rough printed edges, thus reducing the contact current conducting capability relative to trace applied by a continuously-discharging applicator. One manner of increasing contact quality and reducing linewidth is to use very small drops by aerosolized drop generation, but these systems are also limited by throughput and reliability. Another means is to use microsyringe extrusion applicators, but these are also limited by overall throughput as well.